Luteal phase- what is it?

Luteal phase

Briefly said, after the release of the mature egg, the empty follicle collapses developing its own blood supply. It becomes a temporary gland called the corpus luteum. The corpus luteum produces and secrets progesterone, which is the predominant hormone during luteal phase. Progesterone supports pregnancy if it is to occur.

Progesterone’s mains functions:

  • reducing inflammation
  • calming the nervous system
  • soothing mood and improving sleep
  • stimulating the building of bone tissue, and keeping oestrogen in check

Important: if you are taking hormonal birth control containing progesterone, you won’t get all this positive health benefits. This is because the progesterone in the pill is actually progestin and they are different molecules. Your body will produce progesterone when you ovulate and this is not the case if you are on the pill as ovulation doesn’t occur at this stage.

Progesterone will slow you down and you might feel like needing more rest. You might also feel that your digestion is slower during your luteal period. These are because your body wants to protect you and it prepares in case it has to support a pregnancy. The digestion might be slower because your gut will use its’ energy to support a developing embryo.

Your appetite might change and you might feel hungrier. Make sure you feed yourself correctly because otherwise your blood sugar will be unstable, making you crave and eat whatever you have at hand. Avoid comfort food and go for foods that are loaded with protein and complex carbs.

The production of progesterone can be detected as a rise in your basal body temperature. In the case you have conceived, progesterone will continue to be produced and 18 consecutive high temperatures will be the indicator for a suspected pregnancy.

If implantation happens, the cells in your endometrium swell and make your endometrium thicken to about 18mm (compared to 4mm at the start of the cycle). If implantation does not happen, your corpus luteum begins to disintegrate and about day 26 of a 28-day cycle, its secretory function ends. Menstruation begins and you return to your follicular phase.

Characteristics of luteal phase:

  • The luteal phase begins after ovulation. It lasts about 14 days (unless fertilization occurs) and it ends just before menstruation.
  • The hormonal changes of the luteal phase are associated with common PMS symptoms, such as: mood swings, headache, acne, bloating and breast tenderness.
  • Luteal phase is progesterone dominant.

Luteal phase and emotions:

As there are hormonal changes during the luteal phase, specialists also noticed a drop in levels of serotonin, a brain chemical sometimes called the ‘happy chemical’. During this phase, you might start to feel a bit irritable, moody and even angry. For many women, symptoms of PMS start between 4 and 10 days before menstruation will occur.


If you suffer from PMS, try to increase your intake of healthy fatty acids, vitamin B and magnesium. Alternatively, check this or this article I wrote about efficient methods to relieve menstrual pain.

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